Effect of a transverse tensile stress on the electric-field-induced domain reorientation in soft PZT: In situ XRD study

The effect of a transverse tensile stress on the electric-field-induced 90°-domain reorientation in tetragonal lead zirconate titanate (PZT) near the morphotropic phase boundary was investigated in situ using X-ray diffraction (XRD). The XRD intensity ratio, I₍₀₀₂₎/I₍₂₀₀₎, which represents the ratio of the volume of the c-domains to that of the a-domains on the PZT surface, was examined as a function of the electric field at various stress levels. It was found that a transverse tensile stress changes the electric-field dependence of I₍₀₀₂₎/I₍₂₀₀₎, especially at higher electric fields. Without a transverse tensile stress, I₍₀₀₂₎/I₍₂₀₀₎ began to saturate at E ≈ 800 kV/m. With a transverse tensile stress of 75 MPa, I₀₀₂/I₍₂₀₀₎ increased with an upward curvature with the electric field, indicating that the transverse tensile stress enhanced the field-induced 90°-domain reorientation, and increased the effective piezoelectric coefficients at larger electric fields. At E = 900 kV/m, the estimated d_31,domain changed from -200 × 10^-12 V/m at zero stress, to -350 × 10^-12 V/m at 75 MPa.